Note added December 3, 2012. This blog is corrupted and thus rewritten as a wiki; Troubleshooting Issues with VS .NET Datasets and Crystal Reports. Please use the wiki.
One of the more common issues I see on the forums relate to the use of VS .NET datasets and Crystal Reports. For the most part, the issues are; slow performance, incorrect data, no data, prompt for login credentials to a database and more. You may also receive errors such as:
"Unknown Database Connector Error""Failed to retrieve data from the database"“Query Engine Error 'C:WINDOWSTEMP emp.....rpt”“Log on failed...” , etc.
In this blog, I want to describe my approach to resolving these issues. AS a prerequisite, it is assumed that the developer is familiar with creation of datasets and the basic limits when using datasets with Crystal Reports. See the following resources:
Crystal Reports Guide To ADO.NET
Reporting Off ADO.NET Datasets
As always, ensuring that you are working with the latest Service Pack for you version of Crystal Reports should be the first step of your troubleshooting process. Service Packs can be searched in the Downloads section:
https://websmp130.sap-ag.de/sap(bD1lbiZjPTAwMQ==)/bc/bsp/spn/bobj_download/main.htm
If you are seeing the issue on a deployed system, but the application works on your development system, ensure that the Crystal Reports runtime matches the two systems. Latest merge modules and msi files for each version of Crystal Reports (v. 9.1 and higher) can be found through this Wiki:
https://wiki.sdn.sap.com/wiki/display/BOBJ/Crystal+Reports+for+Visual+Studio+.NET+Runtime+Distributi...
A great tool compare the runtime is Modules. Modules can be downloaded from here:
https://smpdl.sap-ag.de/~sapidp/012002523100006252802008E/modules.zip
